The evolution, ecology, and restoration of anadromy in rainbow trout/steelhead Oncorhynchus mykiss

Evolution can occur on ecologically relevant timescales, creating the potential for a bidirectional link between evolution and ecology. For example, migrating species provide important pulses of resources to recipient ecosystems, but are increasingly subject to intense selection due to ongoing global change. If heritable variation underlies migration, then contemporary evolution may increase non-migratory life histories, thereby increasing population persistence, but at the expense of important ecological processes. I examine contemporary evolution and its consequences of migration in an economically and ecologically important species, the resident and migratory ecotypes of the species Oncorhynchus mykiss. In Chapter 2, I show that a stream barrier has driven the evolutionary loss of the migratory ecotype in only ∼25 generations. I estimated the genetic contribution to variation in traits underlying the expression of migration and show that in the above-barrier population there has been a 30% decrease in expression of the migratory ecotype relative to the below-barrier population of origin. In Chapter 3, I examine the ecological consequences of this contemporary evolution. I show that the density decreases associated with loss of anadromy consistently had a greater effect on mesocosm ecosystems than the per-capita effects of the ecotypes. In Chapter 4, I use an analytical model to explore whether a population of O. mykiss would evolve toward greater residency in response to increased costs of migration. I find that evolution can rescue isolated populations; populations that persist are those that evolve in response to the changing selection regime on timescales that prevent population extinction. However, when conditions are restored to the pre-disturbance state, the rate of recovery of the migratory ecotype was unpredictable and generally slower than its loss. Finally, in Chapter 5 I review pathways for restoring the migratory ecotype, and how restoration of a life history may differ from restoring a species. Effective restoration of this life history will entail understanding the ecological and genetic mechanisms underpinning the expression of migratory behavior. Together, these chapters highlight that migratory barriers can drive contemporary evolution of the non-migratory ecotype that increases population persistence, but decreases their ecological impacts. More generally, this research highlights the importance of incorporating evolutionary perspectives in manage- ment, conservation, and restoration

Three Members of the LC8/DYNLL Family Are Required for Outer Arm Dynein Motor Function

The highly conserved LC8/DYNLL family proteins were originally identified in axonemal dyneins and subsequently found to function in multiple enzyme systems. Genomic analysis uncovered a third member (LC10) of this protein class in Chlamydomonas. The LC10 protein is extracted from flagellar axonemes with 0.6 M NaCl and cofractionates with the outer dynein arm in sucrose density gradients. Furthermore, LC10 is specifically missing only from axonemes of those strains that fail to assemble outer dynein arms. Previously, the oda12-1 insertional allele was shown to lack the Tctex2-related dynein light chain LC2. The LC10 gene is located ∼2 kb from that of LC2 and is also completely missing from this mutant but not from oda12-2, which lacks only the 3′ end of the LC2 gene. Although oda12-1 cells assemble outer arms that lack only LC2 and LC10, this strain exhibits a flagellar beat frequency that is consistently less than that observed for strains that fail to assemble the entire outer arm and docking complex (e.g., oda1). These results support a key regulatory role for the intermediate chain/light chain complex that is an integral and highly conserved feature of all oligomeric dynein motors

Island Visual Artists '84 : An Exhibition Representing the Work of Island Visual Artists

Williamson gives an anecdotal history of Prince Edward Island's art scene. Includes biographical notes and artists' statements

Island Visual Artists'82 : An Exhibition Representing the Work of Island Visual Artists

Arsenault points out the diversity of Prince Edward Island artists' work. Includes brief artists' statements and biographical notes

Synthesizing the Vertical and the Horizontal: A World-Ecological Analysis of 'the Industrial Revolution', Part I

\u27The Industrial Revolution\u27 is simultaneously one of the most under-examined and overly-simplified concepts in all of social science. One of the ways it is highly under-examined is in the arena of the ecological, particularly through the lens of critical world-history. This paper attempts to analyze the phenomenon through the lens of the world-ecology synthesis, in three distinct phases: First, the history of the conceptualization of the Industrial Revolution is examined at length, paying special attention to the knowledge foundations that determine these conceptualizations. Secondly, I sift out what I believe is the dominant model throughout most of modern and now postmodern history, which I identify as the techno-economic narrative. I then present the main critical world-historical challenge to that argument (that the Industrial Revolution was a unified, linear, two-century phenomenon) by outlining the critical interpretations of Fernand Braudel, Immanuel Wallerstein, Giovanni Arrighi, among others, leading a view of industrialization that is over the very long term, or what Braudel referred to as the longue durée. This long-view form of critical historical analysis is unabashedly Marxist, so there is some foray into various pieces of the Marxian canon, pieces that are often left untouched or at the least under-utilized in many politico-economic analyses of environmental history and politico-ecological narratives as well. Thirdly, I attempt to bring this new long-form view of industrialization more firmly into the ecological, but filtering the basic presuppositions of the \u27techno-economic\u27 narratives and the Marxist \u27critical world-historical\u27 narratives through the presuppositions of Jason W. Moore\u27s world-ecology synthesis. What we arrive at through this filtering process is a very different view of the Industrial Revolution than we are used to hearing about. This is Part I of a much larger research process, one that I intend to bring into the present and future by looking at the development process of the BRICS as the next extension of the Industrial Revolution. What this paper is most concerned with is re-igniting what I think is a valuable debate among theorists, economic historians, and Marxist ecological thinkers, the debate about what exactly this phenomenon was, is, and will be. My small contribution is to re-define it in relationship to its really-existing history, including its antecedents and possible future expansions